Question

A boy has 11 coins in dimes and quarters. Their value is $1.70. How many of each does he have? Which of the following equations could be used to solve the problem? x + (11 - x) = 1.70. 25x + 10(11 - x) = 1.70. 0.10x + 0.25(11 - x) = 1.70

Answer 1

the answer is c 0,10x+0.25(11-x)=1.70

Explanation:

If he had all dimes it would be 1.10 but there is 60 cents left over.

So you would multiply 0.10 by x and add 0.25 times 11-x to get your answer

Answer 2

x - number of dimes, y - number of quarters
x + y = 11
0.10 x + 0.25 y = 1.70
0.10 x + 0.25 ( 11 - x ) = 1.70
We can solve it:
0.10 x + 2.75 x - 0.25 x = 1.70
0.15 x = 1.05
x = 1.05 : 0.15
x = 7 ( a boy has 7 dimes and 4 quarters )
Answer: D ) 0.10 x + 0.25 ( 11 - x ) = 1.70